Compatibility of Visual Micro Projects With the Original Arduino
IDE

If you ever decide to move away from Visual Micro, back to the original Arduino
IDE, or if you want to share your projects with people not having Visual Micro,
then you should obey a few rules.

The following table shows features of project structure that are exclusive to
Visual Micro. If you have used one of these features, then the table shows you,
what to do, to make your project compatible with the Arduino IDE again.

Arduino IDE has no concept of "projects" and compiles every .ino
or .cpp file it finds in the disk folder.Files you had removed from
your Visual Micro will become part of your sketch again, if you are
using Arduino IDE.

...gave your source files filenames that:

start with a number (like "0file.cpp")

contain blanks (like "my file.cpp")

are longer than 30 characters

Change the file names, so that they compile with these
restrictions

Arduino IDE cannot handle source filenames that start with a
digit, contain blanks, or are longer than 30 characters.